Gaseous tube and circuit



Oct 11, 1949.

FIG. 2.

FIG. 3. 672 2 3 4 6' 6 67'! c. J. FITCH ET AL 2,484,084

GASEOUS TUBE AND CIRCUIT Filed Nov. 27, 1945 INVENTORS C.J.F/TCH BY RME/CHORN FIG. I.

'ATT'ORNEIY Patented oer. 11, 1949 UNITED ST TE GASEOUS TUBE AND CIRCUIT v tt, and Robert N. Eichorn,

Clyde J. Fitch, Endico Vestal, N. Y., ass

ore

to International Business Machines Corporation, New York, N. Y., a.

corporation of New York Application November 27, 1945, Serial No. 631,095

1 Claim.

1 This invention relates .to an electronic tube and to a circuit in which the tube is employed.

One object of picked up without drawing current through the load circuit and then transferred to the load circuit at a later time.

Another object is to provide a gaseous trigger tube so constructed that a number of tubes can be inserted in parallel load circuits and individually ignited at diiierent times.

In the copending application of Pitch and Eichorn, Serial No. 623,024, flied October 18, 1945, now Patent Number 2,456,825, there is described a distributor comprising selective storage of the signal elements of a combinational code signal. The storage devices include gaseous trigger tubes having their plates connected through respective plate resistors to the B+ voltage supply and, in parallel to said plate resistors, individual control magnets which are normally disconnected from the B+ voltage but can be connected thereto by a gang of relay contacts. On receiving a signal, the trigger tubes are selectively ignited and their arcs held through the' plate resistors and finally the'relay contacts are closed and the plate circuits extended through the'respective control magnets.

It is a particular object the present invention to provide an improved trigger tube which can be employed in a circuit of the type shown in the copending application and which will eliminate the need for a gang of relay contacts.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode. which has been contemplated, of applying that principle.

In-the drawings:

Fig. l is a perspective cut-away view of an storage devices for the the invention is to provide a gaseous trigger tube in which the arc can'be improved trigger tube constructed in accordance,

with the invention.

Fig. 2 is a diagram of a circuit employing six trigger tubes of the type shown in Fig. 1.

Fig. 3 is a diagram of a'combinational code signal to which the circuit is designed to respond.

The trigger tube, as shown in Fig. 1, is similar to a thyratron oi the type known as a 2050. It has an anode II, a cathode II, a control grid l2 and a shield grid it, all of standard construction. The shield grid is a box-like structure enclosing the other electrodes and having a partition H between the anode and control grid with a window resistances l-G.

i5, providing passage for electrons flowing from the cathode to'the anode.

In accordance with the invention, an auxiliary anode I! is inserted in the compartment con-. taining the main anode l0 and is shown in the drawing as a. small round rod located between the partition I4 and the anode Ill. The electrode structure is enclosed in an envelope H which contains a gas, such as mercury vapor, or one of the inert gases, at a low pressure.

The circuit shown in Fig. 2 is designed for the reception of -signals of the kind shown in Fig. 3, consisting of a start signal ST'I, six code elements i-G, and a stop signal STP. The signal shown in Fig. 3 is the combination 5. The stop signal and the code elements 2, 4 and 5 are represented by marking conditions while the signal elements I, 3 and 8 and the start signal are represented by spacing conditions.

The circuit comprises six gaseous trigger tubes Gl-Gi of the kind shown in Fig. 1. The cathodes of these tubes are connected by a wire 20 to the negative end of a voltage divider comprising The voltage divider is connected across a suitable D. C. voltage supply represented by +0. I There is also a bias voltage supply across a resistance I, represented by 0-. The control grids'of the tubes Gl-G6 are connected through respective grid resistors 2| and a wire 22 to the negative end of the resistance 1. The shield grids are connected through grid resistors 23, a wire 24, a resistance 25, and a wire 26 to a point 2'! on the voltage divider l-G. The auxiliary anodes are connected through anode resistors 28, wire 2!, normally closed contacts R2a of relay R2, and wire 30 to the positive end of the voltage divider l-G. The main anodes are connected through the respective control magnets Ml-MB to a wire 3| leading to a normally open contact Rid of the relay RI. When the contact Ria is closed, the wire and thence to the divider l4.

It will be seen from the connections described that the control grids of normally have a negative suilicient to prevent even if a positive bias is applied to. the shield grids. In the normal condition of the circuit, the shield grids have a positive end of the voltage bias and this bias is 2| is connected to the wire 30 the trigger tubes Gi-Gi an ignition of these" tubespositive bias, the point I 21 to which they are connected being at a higher potential than the Provision is made for unlocking the gas tubes GI G5 in succession, in time with the respective code signal elements. If at the time the tube G2 is unlocked there is no potential drop in the resistance 25, due to a marking signal condition, the tube G2 will be ignited, the are extending only to the auxiliary anode. If at the time the tube G3 is unlocked there is a voltage drop across the resistance 25, due to a spacing signal condition, the potential on the shield grid of the tube GI will be low and no arc will be struck in this tube.

' The sequential unlocking of the trigger tubes is accomplished by means of a sweep circuit comprising vacuum tubes VII, VI V1- This sweep circuit is similar to one shown in the pending application 01' Clyde J; Fitch, Serial No. 465,604, filed November 14, 1942, now Patent Number 2,424,110. The cathodes of the tubes VI-V'I are connected by a wire 40 to a point 4 l on the voltage divider I-5. Their anodes are connected through the primary coils of respective transformers Tl-T6 and a wire 42 to a point 43 on the voltage divider I--5. The grids are connected through secondary transformer windings and a wire 44 to the arm of the potentiometer 5. The circuit or each grid extends through the secondary .winding of the transformer associated with the preceding tube in the sequence, the circuit of the grid of the tube VI extending through a secondary winding of a transformer T0 associated with the vacuum tube V0. The anode of the latter tube is connected through the primary winding of the transformer T0 and wire 30 to the positive end of the voltage divider I6, while its cathode is connected through a wire 45 to a point 46 on said voltage divider. The grid of the tube V1 is connected through the secondary winding of transformer T6 and the wire 41 to a point 48 on the voltage divider l-B. The anode of this tube is connected through an anode resistor 49 to wire 42 and thereby to the point 43 of the voltage divider I5.'

The grid of the tube VII is connected through a resistance 5| to the cathode of this tube, the tube being therefore normally conductive, which means that plate current flows through the primary winding of the transformer T0. When the tube V0 is rendered non-conductive, in a manner to be described presently, current ceases to flow in the primary winding of the transformer T0 and the field of this transformer collapses. This induces a voltage in the secondary winding which lifts the potential of the grid of the tube VI to a point which renders the latter tube conductive. Also, grid current flows in the tube- VI retarding the collapse of the field in the transformer T0 for a definite time. when plate current begins to how through the primary of transformer TI, a negative voltage -wave is applied to the grid of the tube V2, which is without effect. After a predetermined time the voltage on the grid .of tube VI drops to cathode potential and the grid current ceases to fiow. The field of the transformer T0 then collapses suddenly and the tube VI is cut off, terminating the flow of plate current through the primary winding of transformer TI. The field of this transformer collapses and a positive potential is applied to the grid of the tube V2. Thus, the sweep passes down through the series of tubes VI-VI, the period during which each tube remains conductive being determined for the tubes VI-VS by the position of the arm of the potentiometer 6 and for the tube V! by the position of the point 48 on the voltage divider I-6. As each tube VI-Vli is cut off, a positive voltage wave is transmitted from a point on the primary winding of the related transformer TI-TG, through the wire 53 and condenser 54, to the control grid of the related tube GI-G6. These voltage waves are sharply peaked and timed to occur at the middle of each code element.

During the standby period there is no voltage drop across the resistance 25, but the tubes GI-G6 are prevented from igniting by the negative bias on their control grids. The tube V0 is in a conductive state and current is flowing in the primary winding of the transformer T0. The start of the sweep is controlled by a start tube V8, the cathode of which is connected by a wire 55 to the negative end of the resistance I, the plate of which is connected through a resistance 56, the primary winding of transformer TST, and wire 30, to the positive end of the voltage divider I6, and the grid of which is connected through a grid resistor 51, wire 24, resistance 25, and wire 25 to the point 21 of the voltage divider I6. The tube V8 is therefore normally conductive. When the start signal arrives, a voltage drop is impressed across the resistance 25, depressing the potential on the grid of the tube V8 and cutting off the flow of current through it. The field of the transformer TST collapses and a positive voltage wave is transmitted from the secondary winding of the transformer, through a time delay circuit comprising condensers 60 and resistance 6| to the control grid of a gaseous trigger tube G9. The cathode and shield grid of this tube are connected by wire 52 to the negative end of the voltage divider I--6, while the control grid of the tube is connected through resistance 5|, the secondary of transformer TST and wires 53 and 55 to the negative end of the resistance 1. The positive voltage wave transmitted from the transformer TST removes the normal negative bias of the control grid of the tube G9, which is ignited. When this occurs current passes from the point 45 on the voltage divider I6 through wire 45, resistance 5|, wire 55, the plate-tocathode path of a vacuum tube V9, the platetocathode path of tube G9 and wire 62 to the" negative end of voltage divider I5. The voltage drop across resistance 5| cuts off the tube V0, starting a sweep which proceeds in the manner previously described.

The delay circuit 50, BI is designed fora delay of one-half signal baud, so that the sweep begins at the mid-point of the start signal. Assuming the signal to be the combination 245, as shown in Fig. 3, the positive voltage wave applied from the transformer TI to the control grid of the trigger tube GI finds a spacing signal condition (slgnal element I) across the resistance 25, which depresses the potential on the shield grids of the tubes Gl-G5 and prevents the tube GI from being ignited. The positive voltage wave from the transformer T2 to the control grid of the tube G2 finds a marking signal condition (signal element 2) which causes no voltage drop across the resistance 25, permitting the potential on the shield grids of the tubes Gl-GB to rise. The tube G2 is accordingly ignited, the are being held through a circuit extending from-the positive end f the voltage divider l-6, through wire 30, normally closed contact R2a, wire 29, anode resistor 28 of the tube G2, the auxiliary anode of this tube, across to the cathode and, by way of wire 20, to the negative end of the voltage divider l-6. In a similar way the tubes G3 and G6 are not ignited, while the tubes G4 and G5 are ignited.

The positive voltage wave transmitted from the transformer T5 also extends through a wire 10 and condenser H to the control grid of a gas tube G1. The cathode and shield grid of this tube are connected through wire to the negative end of the voltage divider I--6, while its anode is connected through the coil of relay RI and wire to the positive end of the voltage divider. The positive voltage wave transmitted to the control grid of the tube ignites the tube and the relay RI is energized. Its contact Rla closes about the time the positive voltage wave is transmitted to the control grid of the tube G6, and extends a circuit to the wire 30, through said contact Rla, wire 3|, magnets M2, M4 and M5 in parallel, the anode-to-cathode paths of the related tubes G2, G4 and G5, and wire 20 to the negative end of the voltage divider i-6, energizing said magnets. The magnets MI, M3 and M6 are not energized because the tubes GI, G3 and G6 are not ignited. The closure of contact Rla also extends a circuit through the coil of relay R2 and a resistance 14, to the point 46 of the voltage divider l-6, energizing said relay. The contact R2a opens and the B+ potential is removed from the auxiliary anodes of the tubes Gl-GS.

After a predetermined time the field of the transformer T6, which was last energized, collapses and a positive potential is applied to the grid of the tube V1 which becomes conductive for a period determined by the position or the point 48 on the voltage divider |-6. A negative voltage wave is transmitted from the plate or the tube V1, through wire 15 and condenser 16 to the grid of the tube V9, cutting oi! this tube and thereby deionizing the tube G9. The tube V0 becomes conductive again and the sweep circuit is restored to standby condition.

When the vacuum tube V1 ceases to conduct, a positive voltage wave is transmitted through wire 11, and condenser 18 to the control grid of a gas tube G8, which becomes ignited. Current flowing from the positive end of the voltage divider l-6, through the resistance 19, the plateto-cathode path of the tube G8, and wire 20, to negative end of voltage divider i6, causes a negative voltage wave to be transmitted through a condenser 80 to the plate of a gas tube G1, which becomes deionized. The relay RI is deenergized and its contacts Rla opens, removing positive potential from the main anodes of the tubes Gl-GB. The relay R2 is deenergized, its contact R20. closes, and B+ potential is restored to the auxiliary anodes of the tubes Gl-G6, after the arcs have been extinguished in any of these tubes which were in conductive state. The coil of the relay R1, the condenser 80 and the resistance 79 form a resonant circuit in which oscillations occur when the relay BI is deenergized. The first negative wave of these oscillations depresses the potential on the anode of .the tube G8 and extinguishes this tube, restoring the ch'cuit to starting condition.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied-to asingle modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated'and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claim.

What is claimed is:

In a distributor, a direct current voltage source, a plurality of gaseous trigger tubes, each comprising a gas filled envelope containing a cathode, a first grid, a second grid, an auxiliary anode, and a main anode; means connecting the cathodes. the first grids, and the auxiliary anodes of said tubes to said voltage source so that each of said first grids has a negative bias sufiicient to prevent its tube from ionizing, each of the auxiliary anode connections containing a resistance, a load 1 device for each of said tubes, each load device being connected to the main anode of the related tube, means including a normally open contact for connecting all of said load devices to a positive point of said voltage source, means for raising the potential on the first grids of said tubes in succession to unlock the same at diiIerent times, means for varying the potential on the second grids of all of said tubes concurrently, between a low value which will prevent ionization of the tubes and a high value which will permit ionization of any tube having the potential on its first grid raised, said last means being timed in relation to the means for raising the potential on said first grids so that the high value potential on said second grids coincides with the raising of the potential on the first grids of selected ones of said tubes, whereby arcs are started between the cathodes and auxiliary anodes of said selected tubes, and means for closing said normally open contact to complete circuits through the main anodes of said selected tubes and the related load devices.

CLYDE J. FITCH.

ROBERT N. EICHORN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,731,687 Slepian Oct. 15, 1929 1,746,670 Meyer Feb. 11, 1930 2,060,506 Knowles Nov. 10, 1936 2,099,065 Holden Nov. 16, 1937 2,134,577 Putzer Oct. 25, 1938 2,188,159 Rockwood Jan, 23, 1940 2,210,574 Fitch Aug. 6, 1940 2,272,070 Reeves Feb. 3, 1942 2,329,792 Skellett Sept. 21, 1943 2,332,977 Skellett Oct. 26, 1943 r Certificate of Correction Patent No. 2,484,084

- CLYDE J. FITCHET AL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 29, for the patent number 2,424,110 read 2,421,606;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 7th day of March, A. D. 1950.

THOMAS F. MURPHY,

Aesz's tant Commissioner of Patents.

October 11, 1949 

